Mangroves and fishes: issues of diversity, dependence, and dogma

Tropical estuarine fishes are inextricably linked with mangroves, which are the dominant vegetation of tropical and subtropical estuaries. Among the most productive of aquatic areas and heavily exploited, their future may depend upon ecosystem understanding. This paper reviews diversity, dependence, and connectivity between mangroves and fisheries in the light of data from previously unstudied systems in developing countries and new approaches in developed countries. Fish diversity in mangroves varies at global, latitudinal, regional, local and habitat scales, and species composition in any one system represents the combined influences of factors operating at each of these scales. Mangrove dependence paradigms require critical evaluation as new data become available and as catches and mangrove areas decline. Although it is a widely held dogma that mangroves are essential for fish populations, most evidence is circumstantial. Therefore experimental and quantitative studies are needed to support arguments that the value of retaining mangroves exceeds that of their destruction.